An inkjet recording device well known in the art records images on paper by ejecting ink stored in an ink cartridge onto the paper through nozzles formed in a recording head. When ink in the ink cartridge is consumed through image-recording processes performed by the inkjet recording device, the empty ink cartridge is removed and replaced with a new ink cartridge filled with ink.
The conventional ink cartridge has an ink supply unit for supplying ink, and an air communication unit that provides communication between a layer of air in an ink chamber that stores ink and the exterior of the device. The air communication unit is closed when the ink cartridge is stored so that the ink chamber is kept enclosed. When the ink cartridge is mounted in the inkjet recording device, the air communication unit is opened so that the ink chamber can be in communication with ambient air.
The air communication unit is preferably opened to the external air prior to the ink supply unit when the ink cartridge is mounted in the inkjet recording device. If the ink supply unit were opened before the air communication unit while the ink chamber is in a sub-atmospheric pressure state, ink may flow from the recording head connected to the ink supply unit to the low-pressure ink chamber. This action could break the meniscus of ink in nozzles of the recording head. Even if the pressure in the ink chamber has not been reduced to below atmospheric pressure, an excessive amount of ink may be supplied from the ink chamber to the recording head when in high-altitude regions or areas having an atmospheric pressure lower than the internal pressure of the ink chamber. Such a phenomenon can also break the meniscus of ink formed in nozzles of the recording head.
One example of an ink cartridge mounted in an inkjet recording device includes a single valve mechanism for opening and closing both an ink channel and an air channel (see Japanese Patent Publication No. 4506301, for example). With this ink cartridge, an ink delivery tube inserted into a through-hole formed in a tubular member moves the tubular member through a frictional force generated between the two to open the air channel. Subsequently, the ink delivery tube moves a valve element against an urging force of a coil spring to open the ink channel.